Fouling

Permeate flux decline is a major item when considering pressure driven membrane filtration. The decline is a result of the deposition of (dispersed) feed materials as a layer on the membrane surface. This means loss of production of permeate or, when applying a higher compensating pressure, loss of

Nanofiltration of process liquors from viscose-type textile fibre production was investigated using a laboratoryscale crossflow test apparatus. Feed solutions contained about 200 g/l sodium hydroxide and a high concentration of hemicellulose as a contaminant originating from the raw material wood. T

The effect of solute size relative to membrane pore size on the critical flux during the ultrafiltration of protein solutions was investigated using the constant pressure method. Hydrophilic regenerated cellulose membranes with a cut-off of 10, 30 and 100 kg mol!1, model proteins and skimmed milk so

A membranes hydrophobicity, surface roughness and charge can all affect its tendency to foul and its subsequent cleanability. In this study polysulphone (PSf), polyethersulphone (PES) and regenerated cellulose (RC) ultrafiltration (UF) membranes were fouled with spent sulphite liquor (SSL) and clean

The development of membrane technology has reached a state whereby operational optimisation is becoming the major issue to both researchers and industrial operators. A key focus is towards sustainable operation where fouling is limited and cleaning is greatly reduced. The paper presents an example o

Textile effluents usually contain high concentrations of inorganics as well as organics, and are therefore difficult to treat. Membrane processes can be used for many of these wastewaters in the textile industry. Two typical examples are discussed: (1) the use of nanofiltration for the treatment of

Membrane bioreactors (MBR) combine biological processes with membrane filtration. The main obstacle to efficient operation remains the deterioration of membrane permeability with time. One possible approach to the fouling issue is sub-critical flux operation. Other options are air sparging and backf

Membrane fouling is one of the main factors affecting the diffusion of membrane bioreactors to wastewater treatments. Fouling is generally held to persist above a so-called “critical flux”, below which a steady-state membrane permeability is assumed to be attainable. However, a number of recent stud

This laboratory scale study investigated the effectiveness of ultrafiltration (UF) technology for treatment of refinery wastewater using powdered activated carbons (PACs) and coagulant. Flux decline, removal rates of total organic compounds (TOCs) and the possibilities of membrane cleaning during in